Med (New York, N.Y.)Jul 22, 2026

Ethical issues in gene therapy

CRISPR Gene Editing Weekly Brief ↗PubMed ↗DOI ↗

Updated Jul 23, 2026

Abstract

CRISPR-Cas systems and related technologies have enabled precise genetic interventions for previously untreatable monogenic disorders.

Heritable genome editing is ethically contentious and should not be uniformly prohibited.
Three targets for heritable editing are identified: catastrophic monogenic disorders, polygenic risk reduction, and non-disease trait enhancement.
Heritable editing may be justified for catastrophic monogenic conditions when preimplantation selection fails to produce unaffected embryos.
Current scientific uncertainty limits the clinical application of polygenic interventions due to insufficient predictive validity and poor understanding of broader effects.
The case for enhancement interventions is weak, with significant risks of social stratification and a lack of supporting evidence.
Governance frameworks should allow evidence-supported interventions under strict safeguards while prohibiting those without sufficient evidence.

Simplified

CRISPR-Cas systems, base editing, and prime editing have made precise genetic interventions possible, and several approved therapies now treat monogenic disorders that were previously untreatable. Heritable genome editing remains ethically contested. We argue that heritable interventions should not be treated as a single category subject to uniform prohibition. We distinguish three targets: catastrophic monogenic disorders, polygenic risk reduction, and non-disease trait enhancement. For catastrophic monogenic conditions in which preimplantation selection cannot yield unaffected embryos, heritable editing is permissible, and the duty of beneficence toward future persons may require it. When the alternative is certain severe suffering or early death, the expected benefits clearly outweigh the risks. For polygenic interventions, current scientific uncertainty makes clinical application premature: predictive validity remains insufficient and pleiotropic effects are poorly understood. For enhancement, the case is weaker still. Some of its benefits are positional; the risks of social stratification are significant; and the evidence base is absent. We conclude that governance frameworks should permit what the evidence supports under stringent safeguards and prohibit what it does not. The central ethical questions concern welfare, not appeals to nature or abstract notions of dignity. Where the evidence warrants it, failing to pursue heritable gene therapy responsibly may itself be an ethical failure. We outline a translational pathway for ethical germline gene editing.